Studies of microtubular elements and Cosiella burneti, the rickettsial agent of "Q fever" in mammals, are to be undertaken with the electron microscope as a major research tool. The emphasis will be on high-quality, high-resolution microscopy in association with cytochemistry, optical diffraction, and various manipulative approaches. Cortical singlet microtubules and exonemal elements of sperm of a frog lung-fluke are to be studied in both negatively-stained and sectioned material after heat treatment. Sequential dissociation of microtubule walls will be followed by direct visualization and optical diffraction information. Axonal microtubules in crayfish nerve cord will be evaluated with the following hypothesis in mind: filamentous matris material associated with the surfaces of these microtubules is a glycoprotein and is somehow associated with axonal transport. Various physical and cytochemical treatments will be used to test aspects of this hypothesis. In the case of C. burneti, long-term cytopathic effects in mouse L-cells and green monkey kidney cells in vitro will be studied, and cytochemical tests for lysosomes will be evaluated in terms of a defense mechanism against rickettsiae. Also, evidence will be sought for a possible relation between rickettsial infection and multiplication of "A type" virus particles in infected L-cells. Finally, high-resolution studies of the substructure of the cell wall of C. burneti will be undertaken, especially in particles undergoing binary fission.